It is well-known in the art that it is a desirable feature of a liquid hard surface cleaning composition that it should have a certain viscosity. Indeed, viscosity allows a controlled handling, more specifically dispensing of the composition during use, as compared to a thinner composition. Also, viscosity allows a better action of the composition on non-horizontal surfaces, such as toilets, bath tubs and the like. That is because viscosity prevents the composition from running down said surfaces, like thinner liquid compositions would.
Preferably, viscosity will be built up by a so-called "self-thickening system" as opposed to using a thickener for that specific purpose. Indeed, thickeners, such as gums or polymers have at least one drawback that they affect the formula cost, while providing only one benefit, which is thickening. They do not participate to the actual cleaning of the surface and therefore represent "inert" materials. Also, some thickeners are detrimental to the physical stability of the liquid compositions they are formulated in. It is known in the art to formulate self-thickened liquid compositions where the thickening is achieved without the use of polymeric thickeners, see for instance WO 95/03383.
WO 95/03302 discloses an aqueous viscous composition (pH=0.5-7) comprising an amine oxide or amine and a secondary or primary monobranched alkyl sulfate or sulfonate, a hydrotrope and an organic acid.
However, there is still a need to provide self-thickened aqueous compositions with better performance in several respects including cleaning performance like grease cleaning performance and viscosity properties.
It is thus an object of the present invention to provide an aqueous hard-surface cleaning composition which is viscous by means of a self-thickening system and which delivers improved cleaning performance.
Also, there are some drawbacks associated with viscosity. And a main drawback is that viscous compositions are typically difficult to rinse away, specifically because viscous compositions have a good cling onto surfaces and current self-thickening systems lead to the formation of stable foams. Thus, viscosity and ease of rinsing are somewhat conflicting requirements, but both are desirable in a single-composition for cleaning hard surfaces.
It is thus another object of the present invention to provide an aqueous hard-surface cleaning composition which is viscous by means of a self-thickening system, and which is nevertheless easy to rinse away.
It has now been found that the above objects can be met by combining (1) a linear C6-C16 alcohol and/or a linear alkoxylated C6-C16 alcohol, (2) hydrotropic solvent and (3) an anionic surfactant selected from the group consisting of a linear and branched alkyl sulfate, a linear and branched alkyl sulfonate and mixtures thereof. Indeed, it has been found that the compositions of the present invention comprising a linear C6-C16 alcohol and/or a linear alkoxylated C6-C16 alcohol, said hydrotropic solvent and said anionic surfactant deliver excellent viscosity properties and improved cleaning performance as compared to the same compositions containing amine oxide surfactants instead of said linear C6-C16 alcohol and/or linear alkoxylated C6-C16 alcohol. More particularly, excellent viscosity properties are achieved even at lower total level of self-thickening ingredients.
An advantage of the viscous compositions according to the present invention that deliver improved cleaning performance is that they may be used in a wide range of applications in bathrooms, kitchens, floors and especially on any vertical surface like walls, toilet bowls and the like.
An additional benefit derived from said compositions is that they are low foaming, both in the sense of the amount of foam initially generated during use, as well as in terms of foam stability. This benefit adds to the ease of rinsing benefit already obtained with the "mechanistic" benefit derived from the viscosity profile of the composition.
Yet another advantage of the compositions of the present invention is that they are physically stable upon long storage periods.
Actually, the present invention provides a cost effective hard surface cleaning composition that meets consumer needs concerning viscosity, rinse ease, cleaning performance and stability upon long storage periods.